private void FindDroppedIndexes(
Tuple <IEntityType, IEntityType> tablePair,
IEnumerable <Tuple <IIndex, IIndex> > indexPairs)
{
_operations.AddRange(
tablePair.Item1.Indexes
.Except(indexPairs.Select(pair => pair.Item1))
.Select(ix => OperationFactory.DropIndexOperation(ix)));
}